Field of the Invention
The present invention relates to an optical apparatus such as a television lens system and a video lens system, and more particularly, to an image pickup apparatus including a lens apparatus and a camera apparatus.
Description of the Related Art
An image pickup system to be used in a television image pickup situation includes a television lens system (hereinafter, referred to as “lens apparatus”) and a television camera (hereinafter, referred to as “camera apparatus”). As the lens apparatus, there are known a lens apparatus including a manual focusing mechanism for moving a focus lens through an operation by a user himself/herself, and a lens apparatus including an automatic focusing function for moving the focus lens using an image signal from an image pickup device, such as a CCD, so that an object becomes in focus. In the camera apparatus, there is mounted a monitor (viewfinder) for displaying a real-time image that is currently picked up. The lens apparatus including the automatic focusing function is configured to output information on the automatic focusing function to the camera apparatus in response to an instruction from a controller connected to the lens apparatus so that the output information is superimposed on an object image on the camera side and is displayed on the viewfinder. Examples of the information on the automatic focusing function include a focus detection range indicating a range of focus detection in an image pickup range, and a focus state indicating a degree of focusing. The information on the automatic focusing function is herein referred to as autofocus information or focus information.
The user may easily confirm the autofocus information through the viewfinder during the image pickup operation. However, in a case of using a controller having no display instruction unit for instructing the autofocus information to be displayed on the viewfinder, the autofocus information cannot be displayed.
Conventionally, there has been required a technology of displaying the autofocus information independently of the controller.
For example, Japanese Patent Application Laid-Open No. 2009-194523 discloses a technology in which, when it is determined that the controller has no display instruction unit, the autofocus information is output to the camera and the output information is displayed.
However, the conventional technology disclosed in Japanese Patent Application Laid-Open No. 2009-194523 has a problem in that the autofocus information is constantly displayed even in a case where the user wishes to avoid displaying the autofocus information, and hence the autofocus information cannot be hidden when not needed. The viewfinder originally serves to display a real-time object image that is currently picked up, and hence when the information superimposed on the object image, such as the focus detection range and the focus state, is constantly displayed, the user may feel inconvenience depending on an image pickup situation. Further, the controller may include a switch for display switching, but in an image pickup situation in which a strict operation is required as in the television image pickup situation, the user may wish to concentrate on field angle adjustment and focusing rather than the display switching. Further, as described above, there is a case where the controller does not have the switch for display switching, and hence it is desired that whether or not to display the information be determined based on an autofocus operation status and an object status, and the display be automatically switched so that the information is displayed when needed and hidden when not needed.